1. Field of Invention
This invention relates to the operator-system interface of automation controls on audio recording consoles and other computerized systems.
2. Description of Prior Art
In order to fully understand the present invention it is necessary to describe prior art and practices in some depth.
In recording studios where the sound production for records, tapes, motion pictures and the media occurs, the central piece of equipment is the recording console. It coordinates the operation of all other audio equipment in the control room. The recording console contains many controls for functions such as the variable control of loudness, stereo balance, equalization and much more. Before the 1970s, recording consoles were relatively small and manageable due to the fact that studio tape recorders had relatively few tracks, from one to about eight. The more tracks that were available, the more it was possible to record instruments on separate tape tracks and this gave recording engineers more flexibility in making stereo mixdown decisions later on for the intended end product. From the 1970s to the present day, tape recorders with sixteen, twenty-four and more tracks have became available, and recording consoles have become much larger and more complex so as to facilitate the mixing of all those tracks. Individual engineers often found it difficult or impossible to manage a great many control changes by themselves throughout a song or other audio production. For example, an engineer may have successfully managed to create a complex mix that was just right in every detail but one. Then the entire difficult mixing process would have to be run through again to include the one additional adjustment, with attendant possibility for error in remixing previous parts. Often, one or more additional engineers would have to be called in to handle the many simultaneous mixing moves that were needed on a complex or "busy" mix.
The solution to this problem was to introduce computer-assisted mixing for the engineer on the recording console. A means was devised to automate the series of linear-throw volume controls, called faders, across the lower portion of the console's control surface. This left the vast majority of the other variable controls on the console surface, usually all rotary controls, unautomated. However, the greatest amount of continual, dynamic mixing is made through the main faders, and so automating them helped the recording engineer considerably in his work.
Today, when working on an automated console, a recording engineer begins a stereo mixdown by playing the multitrack master tape and adjusting fader knobs up and down just as he had in the past. However, the mixing done on the faders by the engineer is "remembered" by the console's central processing unit (CPU). After a song has been played through and mixed, the engineer can rewind the tape and play it back, and all the fader levels he mixed are automatically reproduced including all static and changing levels. It is then a relatively simple matter for the engineer to continue to go back and do additional mixing as necessary without having to redo all of the work he had done previously. It also makes the refining of a complex production requiring twenty, thirty or more mix passes immensely easier. The vast majority of mixing decisions from previous mix passes that were satisfactory continue to be reproduced automatically, while the engineer can concentrate on subtler and subtler refinements. This technology, in large part, makes possible the high quality, state-of-the-art recordings and soundtracks heard today.
The first type of automated fader was the voltage controlled amplifier, or VCA, fader. Whereas on nonautomated consoles a facer controls an audio signal directly with a variable resistor, the VCA fader varies a voltage representing a changing audio level in a voltage controlled amplifier. When a VCA fader is placed in the write mode, all control voltages generated by movements of the fader that the engineer makes are recorded in the automation computer as digital codes representing the control voltages. When the VCA fader is placed in the read mode, the fader's knob does not move, but all of the audio control levels previously written in digital code are reconverted to voltages and sent again to the VCA. In this manner, audio levels are reproduced during automated playback. The computer system also provides a mode called update or relative update for each channel fader for the purpose of programing refinements to a fader's overall recorded control levels while preserving the previous, individual "moves." In technical terms, update is the adding of additional amplitude modulation to a previously amplitude modulated signal.
In spite of the convenience of VCA fader automation, it contains certain idiosyncrasies that an engineer must contend with. For example, if an engineer wants to rewrite a section of a track in the middle of a mix, he usually cannot simply push the write button and begin mixing. The instant that he pushed the button, there would be an abrupt jump in loudness between the previously programmed level at that moment in the recording and any new level represented by whatever position the fader's knob now happened to be in. The engineer has no way of knowing where the knob was previously set at that point (unless he had memorized it) and therefore he cannot move the knob to the correct point in advance to match it. Alternatively, if an engineer wants to update a track at any point in the recording using the update mode, he must contend with other hindrances which vary according to the different existing VCA fader systems and the general characteristics of VCAs. Most of the problems with VCA faders relate to the function of update, as described below:
a) In previous systems, update required that the fader knob be set in advance to a special position called a null point at a median distance along its throw. At this null point, the new update level is ready for perfect matching to any previously programmed control levels, regardless of what they were. When update is punched in anywhere in the audio mix, it will be entered without causing an unacceptable sudden jump in audio level. However, the position of the knob during update is no longer representative of the audio base level which was programmed during a previous pass. This adversely alters the natural physical headroom, positioning and "feel" of the fader for the engineer. More seriously, however, the engineer may now be severely limited in terms of what he can do. If, for example, the original knob position and corresponding audio level was near the bottom of the throw, and the engineer now desires to make a considerable increase in fader level, he no longer has the physical headroom to do so. Starting from the median null point, his fader's knob will come to an abrupt stop at the physical top of the fader's throw, which is a far smaller travel than starting near the previous knob position which was recorded near the bottom of the throw. Conversely, if the originally programmed level was nearly full open, that is, with the fader knob near the top of the throw, and the engineer, now mixing in update mode, desires a fade out which he must do from the null position, he will find that he can bring the fader's knob to the very bottom of the throw without being able to completely fade the channel out. Finally, the engineer has to be careful to return any faders in the update mode to their null points before the end of a mix pass, otherwise an abrupt jump in level will occur when switching out of update. The engineer has to be careful since it might be difficult or impossible to return more than one or two faders to their null points quickly yet smoothly before the end of a mix pass, depending upon how "busy" the mix was.
b) Some previous VCA automation systems featured a null range rather than a null point. This made positioning of the knob to the null position a less exact and time-consuming process. However, this simultaneously provided a potential for even greater knob position and audio level disparity than has been described in a).
c) Most of today's systems no longer require that the fader be preset to any null point or range at all during update, and any position that the fader is in is designated as the null point upon each start of a programming pass. Therefore, the fader is ready for update, or is at least in the null mode, automatically, at any time that update is initiated. However, just as the null range described in b) could throw off knob headroom even more than the null point of a), so does this system potentially create the most extreme headroom problem of all. For example, a fader could be entered into update mode when the fader's knob is at the very top of its throw with perfect level matching, but with no capacity at all to increase levels. If the fader's knob were at the bottom, fader level could not be reduced by any amount. This degree of restriction is partially dependent on how predictable or unpredictable and complex the mix is, and how much time the engineer has to spend in advance to readjust controls to try to assure that most controls will probably have all the headroom that they need.
d) Even on the world's only fully automated recording console, the Series Ten by Harrison Systems, which provides automation of all variable controls across its control surface, update for the extra controls proved to be unworkable and unmarketable using conventional technology. On the Series Ten, the quantity of potentiometers was greatly reduced by making a smaller number of potentiometers multi-functional, that is, function-assignable. In Harrison's attempt to provide update on the potentiometers above the channel faders, they decided to go back to operating the control similar to the way as was described for faders in "a" above. That is, it was always necessary for the operator to adjust a potentiometer to a precise null point before update with that control could be considered. In this case, however, the null point was not always the same arbitrary position as described in "a" above, but at whatever previous position exactly matched, and was therefore an accurate physical representation of, the actual audio control level. This null point would have to be painstakingly matched by the engineer, the match being successful and indicated when a light emitting diode came on. This was apparently Harrison Systems' attempt to always provide full headroom at all times for all potentiometers, which this often accomplished, as opposed to the typical VCA complications described above. However, primarily due to the confused knob positioning their system caused, which is related to the potentiometer's inability to physically track dynamic moves from the previous mix even after it had been "nulled," update for potentiometers had to be abandoned on the Series Ten. For one thing, every time that it was desired to stop and then continue mixing in the middle of a song, any potentiometers in the update mode with previous dynamic programming would have to be physically reset to match the current base audio levels existing at that instant. For another, since Harrison was using potentiometers that were function-assignable and therefore required two operator moves per adjustment--choosing the function and then adjusting the control--the Series Ten, already a slow console, proved to be doubly slow. Cinema mixing engineers, for example, have complained that the Series Ten is too slow for their work, and that instead of a few assignable controls, they want many single-function "grab and go" controls. And yet, the Series Ten is not all that slow when the fact that it is fully automated (now minus update on potentiometers) is taken into account. Total console memory speeds up many aspects of the mixing process, especially the recreation of a previous mix. The Series Ten, the most advanced and expensive recording console in the world, simply represents another compromise.
e) Although quality can be quite high, many engineers claim to be able to hear subtle distortions that VCAs may add to audio, as compared to the measurably cleaner audio signals in standard, nonautomated controls.
So, even with most of today's VCA faders which have no localized null point or range, an engineer must constantly reset faders as necessary to reduce the likelihood of running out of physical and operational headroom. If he wishes to be prepared to move any faders once he starts an update mix pass, he must adjust them all to some median point along their throw. Since the typical console today has at least twenty-four to forty-eight or more faders across the lower portion of the console, doing this can be time consuming as well as a constant encumbrance to the creative flow in the studio. If a song is, say, three minutes long, an engineer may need to take the time to readjust faders every three minutes or at the end of each mix pass. Engineers either never bother to prepare fully for update, or they may resort to primitive measures such as taking a yardstick to collect all faders and press them fully down, then move them all up to equal median positions along their throw. Again, it must be remembered that, in spite of this, the faders may still run out of headroom, causing problems such as being unable to fade a channel completely out. This is part of the reason why it would not make mixing a great deal easier to add conventional automation capability to all of the other controls on the console surface which number in the hundreds. Nearly all the other controls are rotary controls, where one cannot even use the trick of a yardstick to quickly set them to a median range. Plus, as described for the Harrison Series Ten, it would be essential for the physical position (rotation) of the knob to be correct and exactly match its individual previous physical position. Also, with dynamically changing levels, the previous physical position of each control on the Series Ten is different from point to point throughout a song, requiring still more resetting each time it is desired to start automated mixing from a new point. And on any fully automated console, resetting to an exact null point would also be unavoidable in the case of a panoramic potentiometer, or pan pot, which is used to "pan" a signal anywhere from left to right in the stereo panorama. The position line on the top of the knob or the protuberant pointer along the knob's vertical length should always be a perfect indication of its true pan position, another reason that the engineer must take the time to match levels precisely before updating. Even if it didn't cause a level jump by not resetting the control, if the representative position of rotary knobs were allowed to vary from the audio base level of a previous pass, mixing would become immensely confusing. Imagine trying to make adjustments on a pan pot when its knob is visually indicating a pan somewhere to the left of center while the actual panned balance is somewhere right of center. The same situation applies to other functions such as the one controlled by the frequency knob of a channel equalizer, for example. If the knob is pointing at 400 hz, then the engineer has to know that the knob is telling him the truth, instead of modifying frequencies at somewhere above 1,000 hz.
Another somewhat hidden and subtle awkwardness in VCA faders is that the engineer does not have the advantage of a fader knob position which always gives him an anchored, reassuring level indication to help him make further mixing decisions. For example, on an "old-fashioned" nonautomated fader, any knob position consistently represents an exact audio level. This is very helpful to the engineer in making present and future mixing decisions based upon its position in past mix attempts. The engineer, in other words, does not always have to rely one-hundred per cent upon his ears at all times, but is aided by visual physical reference points, not only for one particular fader, but also for the comparative levels of all faders across the length of the console. For example, an engineer can get used to, and rely on, the sonic meaning of certain knob positions in relation to the sound it is controlling in a particular song and the relation of other knob positions to the overall mix. This aspect is of importance particularly when a very fine, precise mix is desired requiring knob movements of small fractions of an inch, against the lined and numbered escutcheon on the faceplate below the knob. VCA faders, who's relative knob positions to audio levels become grossly inaccurate after the first mix pass due to updating, take away this reference point that engineers otherwise enjoy on nonautomated faders.
The second type of automated fader which has been available since the mid nineteen-seventies is the motorized fader. This fader is essentially the same type as the standard nonautomated fader, both using a carbon-based or conductive plastic wiper variable resistor element. The main difference is that this automated fader uses a motor. A motorized fader is initially moved up and down by the engineer, just like any other fader. However, when a mix is played back, the motor is engaged and the knob moves up and down by itself along its throw, duplicating the actual physical moves that the engineer had just made. The motorized fader has certain advantages over the VCA fader. Probably its most important advantage is that the motorized fader's knob position precisely corresponds to its actual audio level at all times. It is probably for this very reason that, although the British-made motorized faders were at first laughed at by American engineers as being clumsy and archaic, they have, for lack of anything better, become arguably the most popular type of automated fader today. When the motorized fader's knob is near the bottom of the throw, audio level is low. When the knob is near the top of the throw, audio level is high, exactly like a nonautomated fader. A motorized fader never needs to be reset, eliminating the time-consuming resetting, and continual gaging of the current existing headroom, of VCA faders. Another advantage of the motorized fader is, unlike the VCA fader which may produce audible distortions, the motorized fader's audio signal is exceptionally clean and clear. And, with a motorized fader, it is also possible to enter the write mode at any time without any abrupt jump in audio level. This is because the motorized fader knob remains in the same position when punched into write mode as it was at the last moment of the previous read mode, and any particular knob position in a motorized fader consistently represents the exact same level for that position in all modes and at all times.
However, the motorized fader has its own compromises:
a) It has always been considered a practical impossibility to motorize all of the variable controls on the console surface. Motorized faders are expensive, and if all potentiometers on the console were automated as well, the expense could add thousands or even tens of thousands of dollars to the cost of an average or state-of-the-art recording console. Therefore, total console automation has never been possible, or at best, is not practical, with motorized controls.
b) Another concern in adding so many motors in a console surface is that they could induce electrical interference in the audio signal as well as greatly increase current consumption.
c) Motorized faders, like any other motors with moving parts and mechanical stress and wear, are subject to degradation of quality and accuracy and to early breakdown as compared to non-motorized controls.
d) Originally, update was impossible on motorized faders. Currently, on motorized faders such as the Neve Flying Faders, it is possible, although awkward, to add update. Since knob position is absolutely tied to audio level in a motorized fader, it is impossible to guarantee that update will occur at the actual time that the engineer is making the adjustment. At the time that his finger is on the fader's knob, stopping any attempt by the motor at physical travel from previous programming, the fader is arbitrarily forced into the write mode. During that time of adjustment, any concurrent, previously written changing fader levels are stopped, and, in effect, erased. It is only after the engineer removes his finger that true, non-destructive update is enabled.
e) Motorized faders can be awkward to catch "on the fly." An engineer can reach for a motorized fader to make an adjustment, and he may find it suddenly flying away from his hand!
f) Finally, there is limited space for adding motorized rotary controls in the tightly packed area of channel electronics above the faders in most if not all existing consoles.
Both VCA and motorized faders share some other disadvantages in common. It is awkward to swap their control functions with other controls. For example, towards the end of a recording session, it is occasionally useful to swap the control functions of a channel's input fader and monitor potentiometer. This is done when it is desired to use the console's monitor potentiometers to continue to record overdubs (backup vocal parts, etc.) while using the faders to start the mixdown which has already been approximated on the monitor potentiometers, thereby saving considerable time. The difficulties are as follows:
a) In the case of swapping VCA faders and potentiometers, the physical headroom of each control would be altered with the attendant physical headroom problems previously mentioned.
b) Motorized faders and potentiometers cannot be swapped during the middle of operation since this would cause a momentary abrupt change in audio levels as the motorized faders swapped their audio connections and physical positions.
Assignability is similar to swapping. Assignability is the ability to switch a control from controlling one signal to another, including that of a completely different function. Neither conventional VCA or motorized console faders are easily suited to this job, because:
a) With VCA faders, headroom immediately changes with the attendant problems listed above. Also, some assigned functions require different different VCA fader or pot throw and turn ratios, and function is compromised, again mainly due to the knob position and headroom problems.
b) With motorized faders, at best, levels would momentarily jump as described above for control swapping in the middle of a function. Also, motorized faders contain a variable resistor element which is only capable of controlling other electrical signals whose control requirements are matched to the particular resistor element in that fader.
It should be reiterated that on automated consoles, all the other variable controls (mostly potentiometers) aside from faders are not automated except on Harrison's Series Ten. (The Series Ten uses resistor ladders known as digitally controlled attenuators, or DCAs, for control of audio signals, but these are essentially the same as VCAs in terms of their described difficulties.)
A number of consoles provide a visual display unit (VDU), also known as a cathode ray tube (CRT). One of the main purposes of a VDU is to provide "snapshots" of all the controls on the console surface. In other words, it displays graphics to show control settings for a particular mix, or for any given moment within a mix. This makes it possible for a master tape to be more easily remixed at a later date, the snapshots providing a visual guide to resetting all of the controls by hand to their previous settings. This is helpful, but nevertheless remains a time-consuming task. A close-up snapshot view only shows a fraction of the console's controls at a time. As soon as one section of the console is reset by hand, the VDU is switched to display another section of the console, and so it goes until the entire process is complete.
Live recording and sound reinforcement situations, such as large rock concerts, magnify all the disadvantages of VCA and motorized faders to a great degree. In live situations, mixing consoles have to be extremely fast and forgiving. In the studio environment, if an error is made, one can go back and correct it--indeed, even refine it to the nth degree. No such luxury exists in live sound mixing. A mistake can be heard instantly by forty-thousand people. Live sound engineers cannot afford the possibility of running out of fader headroom. It would be disastrous, for example, to be out of downward headroom, (e.g. downward travel or range of motion) on a fader when an ear-shattering feedback suddenly occurs on that fader's channel. Thus far, live mixing has been done either on entirely nonautomated consoles, or, rarely, very gingerly with limited automation on automated consoles.
It will be appropriate, momentarily, to discuss specialized controls which thus far have not been used on recording consoles. But first, it is necessary to explain that the previously described VCA and motorized variable controls on the console surface, as well as better than ninety-nine percent of all variable controls used in the world today are known as hard controls and ended controls. Hard means that the control function is fixed or invariable. Ended means that the control comes to a physical stop when either of its two operational extremes are reached. A hard control is typically ended and an ended control is typically hard. With linear-throw knob faders, the physical stop is at the top or bottom of the throw. With potentiometers, knob rotation spans less than three-hundred and sixty degrees before stopping, most commonly from the seven-o'clock to the five-o'clock position, or spanning three-hundred degrees. Inherent in a hard or ended control is the fact that the knob is always in a particular position relative to its two operational extremes.
There are other types of controls called soft controls and endless controls. The term soft refers to the ability of the control to be assigned to control different signals--its function is unfixed and variable. An endless control has no physical stop at either of its two operational extremes and can be rotated beyond them. A linear-throw fader's knob is replaced by an endless belt. A potentiometer knob is smooth with no pointer and rotates endlessly. A soft control is typically endless and an endless control is typically soft. Inherent in an endless control, whether it is configured for soft (assignable) operation or not, is the fact that the belt or knob does not have a physical position along its operational range that is an absolute representation of the level it controls--it is positionless. It only has an non-physical operational position in relation to the work it is performing at a given moment. It typically incorporates what is generally known as a shaft encoder, often utilizing optical technology. The control does not "hold" audio control level at a fixed point as do other controls, but rather generates incremental pulses, typically two square waves at a ninety degree offset, to supply information on amount and direction of movement. The control level itself is held and updated electronically (not physically) in memory. Since an endless control never occupies a physical position relative to (nonexisting) physical limits of linear or rotational travel, and since the control can update with incremental pulses endlessly in either direction, it therefore can never run out of operational headroom. Lacking physical stops, it will also never limit physical headroom. Such a control appears to instantly "match" the existing control level of a function assigned to it. Also, using an electronic display to take the place of the usual visual reference of a fader's knob or a potentiometer's pointer, an accurate indication of the true control level can be made visible at all times.
Since an endless control can never be in a wrong, inaccurate or misleading physical position at any time in relation to the level it is controlling, there is never any of the confusion as to the control level setting that occurs with VCA faders. Also, since there are no limits to the control's physical travel, full headroom for control of normal parameters is available at all times. And since control level matching is automatic, or, more accurately, simply unnecessary since update of control levels is incremental rather than absolute, the recording engineer never has to spend any time resetting controls to null points, or otherwise positioning them to at least hopefully avoid running out of physical and operational headroom. The endless or shaft encoder design can also apply to controls other than level controls, such as stereo balance and equalization controls. In addition, endless controls provide perfect level matching in entering write as well as update modes, unlike VCA controls. Endless controls are not motorized and therefore there is not the possibility of electrical motor noise entering the audio circuitry. Also, since the controls are not motorized, perfect non-destructive update is available at all times without the danger of erasing previous fader moves while the engineer is adjusting the control. Also, unlike motorized controls, endless controls will not suddenly fly away from the operator's hand when he reaches for them. And, endless controls can swap functions with other controls, or be assigned control functions with stored levels, at any time, without changing or running out of physical and operational headroom, and without any momentary jumps in the levels being controlled. In summation, an endless control solves all of the previously described problems associated with conventional VCA and motorized faders.
Until the present time, the use of soft or endless controls in professional audio has been limited mostly to synthesizers, special effects devices, and so-called digital workstations. On these devices, there is generally only a single endless control provided. Its function, being assignable, can therefore replace a great number of separate controls. To date, the only professional audio console that has incorporated a number of endless pots (but retaining some conventional faders) is not a conventional recording console at all but a compact disc mastering console priced in the $100,000.00 range. It is called The Muse by Audio Animation, Inc. The designers of that console have recognized the special value of endless controls and have used them to great advantage in this impressive, highly-advanced console. Operation is very fast, since there are numerous potentiometers which are assigned fixed functions, and they are, in that sense, also hard controls, which means that the operator does not have to assign them a function before using them. There is also one new recording console, the Crescendo by Euphonix, which incorporates one endless/soft control. It is somewhat slow, however. Unlike the Muse, the Crescendo, having only one of these controls which has to be assigned each function one at a time before each use, is too slow for engineers who insist on "grab and go" operation. All of the Crescendo's other pots are conventional in the sense of being ended controls.
At this point it is appropriate to describe three audio level controls which most closely parallel the invention to be described in this application:
1. The first one was called Memories Little Fader which was introduced by Allison Research in the early 1970s. It was an add-on automation device for consoles and it consisted of an auxiliary rectangular box of faders of the endless belt variety to be used in place of the main, non-automated console faders during automated mixing. Each belt was made of clear plastic which was moved by fingertip pressure through which shown a series of LEDs for display of control levels. The unit was used to provide external mix automation to a recording console through electric cabling, temporarily replacing the console's built-in faders. Memories Little Fader was in production for a few years.
2. The second device is the Endless Belt With Digital Output introduced by Penny and Giles of England in 1989. It incorporates an optical incremental encoder, which is a typical embodiment of the shaft encoder mentioned previously. The Endless Belt With Digital Output is provided as an individual fader unit primarily for audio equipment manufactures to mount or retrofit directly into audio systems and equipment. It is similar to a single channel of Memories Little Fader except that the Endless Belt With Digital Output is opaque and a visual display of control levels is not provided with it.
3. A third device is the RC-16 Remote Control by Oxmoor of Birmingham, Ala. It is an endless rotary control with a shaft encoder which has a group of LEDs around the control which the company calls, collectively, a Virtual Pointer, provided for indication of control position. The RC-16 Remote Control is generally not intended for use in recording studios but in public address and background music systems. The increments of level change it provides are too gross (large) for professional audio.
It is believed that none of these controls have ever been used in any professional studio recording console.
If the benefits of soft, and especially endless, controls are so great, eliminating all of the headaches and hassles associated with typical VCA and motorized controls, one would think that using endless controls on recording consoles would be obvious. And, being obvious, manufacturers would therefore completely remove all ended controls on their automated consoles and replace them with endless ones.
However, although automated console manufacturers may (or may not) have occasionally toyed with the idea of using endless controls throughout the console surface in the past, it had been an unworkable idea, previously because the required computer power for this type of control was at first unavailable and, later, too expensive. Although these are no longer insurmountable barriers, a second, somewhat subtler difficulty is even more fundamental. In spite of the overwhelming advantages of endless controls, one thing that would be disorientating for engineers/operators in the device thus far described is, paradoxically, the lack of the physical stop at either of the control's operational extremes. The reason it would be disorienting is that a busy engineer, mixing music let's say, is often watching audio program levels on the meter bridge, or looking at and communicating with performers in the studio area, or otherwise has his eyes directed away from the controls he is operating. He often has no time to even glance at a knob or a representative electronic display to see whether he's reached the top or bottom of a throw. The situation would be even more impossible in live situations in which automated consoles, until now, have been largely unusable. In either case, without a physical stop, a stop relayed to the operator by feel, the engineer may, for example, continue to try to increase a level uselessly if the level has already reached the top of the control range. Conversely, he couldn't know for sure when he's brought the fader all the way down and no longer needs to keep turning it down. This feedback cannot be provided by ear. An engineer may attempt to turn up the volume during a silent passage when there is nothing to turn up, but, not knowing this, and with an endless control, he will attempt to do so anyway. He also cannot know if he is fading a channel all the way down if the program is currently at a silent spot, or if the channel in question is being masked by sound from other channels. Similarly, in the middle of a music mix, one may be able to hear the relative loudness of an instrument, but subjective hearing, which is affected by factors such as monitor level settings, does not provide assurance regarding whether the control is full open or not. The lack of a physical stop makes an endless control, in spite of all its advantages and even if provided with an electronic readout, completely unacceptable for most if not all recording engineers in conventional professional recording console applications.
The invention described and claimed herein solves all of the problems described above for VCA, motorized, hard, soft, ended and endless controls. It is the world's first ended/endless control.